UCERF 3 2 Hazard Implications Hazard comparison metrics

UCERF 3. 2: Hazard Implications • Hazard comparison metrics • Inversion testing – Convergence and eqn. set weighting • Hazard maps – Influence of logic tree branches – Contributions to changes in hazard • Hazard curves at sites 2/21/2013 USGS NSHMP CA Workshop II 1

Hazard Evaluation: Metrics • Ground motion values: – 2% in 50 years (Prob. Exceed. ) – 10% in 50 years (Prob. Exceed. ) – RTGM (1% Prob. Collapse in 50 yr. ) • Frequencies – PGA – 5 Hz – 1 Hz • Curves: • Maps: 2/21/2013 NEHRP (2009) Test Cities Other WGCEP, PBR Full logic-tree for PGA (1440 branches) Partial tree for 1 Hz (40 branches) 2013 USGS NSHMP CA Workshop II 2

Hazard Metrics: RTGM • Risk Targeted Ground Motion (RTGM) • Adopted by BSSC in conjunction with 2009 NEHRP provisions • Ground motion for 1% probability of collapse in 50 years • Computed at frequencies: 5 Hz and 1 Hz • Scalar valued • Considers entire hazard curve 2/21/2013 USGS NSHMP CA Workshop II 3

Hazard Curves: Inversion Convergence • Examine variation over repeated inversion runs • Single “reference” branch • 100 runs San Diego PGA 2/21/2013 San Francisco 1 Hz 2013 USGS NSHMP CA Workshop II 4

Hazard Curves: Inversion Eqn. Weights • Examine effect of varying inversion equation weights • 11 weight variants San Diego PGA 2/21/2013 San Francisco 1 Hz 2013 USGS NSHMP CA Workshop II 5

Hazard Maps: UC 2 vs. UC 3 2/21/2013 USGS NSHMP CA Workshop II 6

Hazard Ratios: Grid vs. Fault Sources 2/21/2013 USGS NSHMP CA Workshop II 7

Hazard Ratios: Grid Source Comparison 2/21/2013 USGS NSHMP CA Workshop II 8

Hazard Ratios: Smooth Seis. Comparison 2/21/2013 USGS NSHMP CA Workshop II 9

Branch Ratios: Fault Models 2/21/2013 USGS NSHMP CA Workshop II 10

Branch Ratios: Deformation Models 2/21/2013 USGS NSHMP CA Workshop II 11

Branch Ratios: Magnitude Scaling Rel. 2/21/2013 USGS NSHMP CA Workshop II 12

Branch Ratios: Dsr (slip along rupture) 2/21/2013 USGS NSHMP CA Workshop II 13

Branch Ratios: M≥ 5 rate 2/21/2013 USGS NSHMP CA Workshop II 14

Branch Ratios: Off-fault Mmax 2/21/2013 USGS NSHMP CA Workshop II 15

Branch Ratios: Smoothed Seis. models 2/21/2013 USGS NSHMP CA Workshop II 16

Hazard Ratio: Sources of Change • Explain all non-yellow areas – Smoothed seismicity model – New faults, slip changes, or Mo rate changes – Methodological changes

Sources of Change: Mmax & M≥ 5 rate UCERF 3. 2 / NSHMP 08 Grid Sources Only (and using only U 2 Smoothed Seis. ) Shows influence of Mmax & total M≥ 5 rate increase for gridded seismicity

Sources of Change: Artifacts UCERF 3. 2 / NSHMP 08 Grid Sources Only (using both U 2 & U 3 Smoothed Seis. ) Artifact of “Deep seismicity” being excluded from denominator map Shows influence of tighter U 3 Smoothed Seis. Model

Sources of Change: Grid Sources UCERF 3. 2 / NSHMP 08 Grid Sources Only (using both U 2 & U 3 Smoothed Seis Map) Influenced by UCERF 3 smoothedseismicity branch Shows influence of tighter U 3 Smoothed Seis. Model

Sources of Change: Fault Sources UCERF 3/UCERF 2 Mo Rate Big Lagoon-Bald Mtn: Extended N ~60 km, and moment rate ~8 times higher on ABM Log 10(Mo ratio); new faults are black

Sources of Change: Fault Sources UCERF 3/UCERF 2 Mo Rate New faults: Klamath Falls Lake E & W Log 10(Mo ratio); new faults are black

Sources of Change: Fault Sources UCERF 3/UCERF 2 Mo Rate Gillem and Cedar Mtn. faults have lower slip rates Log 10(Mo ratio); new faults are black

Sources of Change: Fault Sources UCERF 3/UCERF 2 Mo Rate Four new faults Likely Fault (moment rate doubled) Log 10(Mo ratio); new faults are black

Sources of Change: Fault Sources UCERF 3/UCERF 2 Mo Rate Maacama (20% increase in moment rate) 8 new faults (ABM rates high due to block boundary) West Napa (factor of 3. 5 increase in Mo rate, ABM about 4 times higher than others) Log 10(Mo ratio); new faults are black

Sources of Change: Fault Sources UCERF 3/UCERF 2 Mo Rate Great Valley 07 (Orestimba) moment rate went down by ~60% New Great Valley faults Log 10(Mo ratio); new faults are black

Sources of Change: Fault Sources UCERF 3/UCERF 2 Mo Rate Calaveras (So) Paicines extension Complex combination of new faults and geometric and rate changes Log 10(Mo ratio); new faults are black

Sources of Change: Fault Sources UCERF 3/UCERF 2 Mo Rate New fault: Oceanic – West Hausna (Neo. Kinema rate more than 4 times higher than others) 3 new faults Log 10(Mo ratio); new faults are black

Sources of Change: Fault Sources UCERF 3/UCERF 2 Mo Rate Mix of new faults & gridded sources New fault: Lost Hills New faults in Mojave Log 10(Mo ratio); new faults are black

Sources of Change: Fault Sources UCERF 3/UCERF 2 Mo Rate New Fault: Cerro Prieto New faults: San Clemente San Diego Trough Santa Cruz Catalina Ridge San Pedro Basin Log 10(Mo ratio); new faults are black

Sources of Change: Fault Sources UCERF 3/UCERF 2 Mo Rate Death Valley Faults (North, South, and Black Mtn. Frontal): moment rates went down ~40% Cucamonga: biggest methodological change Log 10(Mo ratio); new faults are black

Sources of Change: Fault Sources UCERF 3/UCERF 2 Mo Rate Anacapa Dume: moment rate down by factor of 3 Log 10(Mo ratio); new faults are black

UCERF 3/UCERF 2 Mo Rate Addition of, or moment rate change on faults Log 10(Mo ratio); new faults are black

Hazard Analysis Sites 2/21/2013 USGS NSHMP CA Workshop II 34

Hazard Analysis Sites 2/21/2013 USGS NSHMP CA Workshop II 35

Hazard Curves: • • • Blue: Logic tree weighted mean hazard curve (UC 3) Light Blue: Logic tree min max hazard curve range Red: UC 2 logic tree weighted mean (solid), min and max (dashed) hazard curves Green: NSHMP reference value Ground motion histogram of logic tree branches summed over weights Tornado diagram 2/21/2013 USGS NSHMP CA Workshop II 36

Hazard Curves: Los Angeles PGA 2/21/2013 1 Hz 2013 USGS NSHMP CA Workshop II 37

Hazard Curves: San Francisco PGA 2/21/2013 1 Hz 2013 USGS NSHMP CA Workshop II 38

Sites with changes > 10% Site Group change Redding WGCEP 287% Brookings WGCEP San Diego Group change San Bernardino WGCEP 88% 257% Malibu West WGCEP 86% NEHRP 137% Eureka NEHRP 86% Carson City WGCEP 127% Long Beach NEHRP 122% Palmdale WGCEP 85% Vallejo NEHRP 121% Santa Rosa NEHRP 83% Northridge NEHRP 119% Oakland NEHRP 82% Big Sur WGCEP 118% Death Valley NEHRP 64% Century City NEHRP 114% Cucamonga WGCEP 59% 2/21/2013 Site 2013 USGS NSHMP CA Workshop II 39

Hazard Curves: Redding (x 3) PGA 2/21/2013 1 Hz 2013 USGS NSHMP CA Workshop II 40

Grid & Fault Conributions: Redding 2/21/2013 USGS NSHMP CA Workshop II 41

Hazard Curves: San Diego (140%) PGA 2/21/2013 1 Hz 2013 USGS NSHMP CA Workshop II 42

Hazard Curves: Vallejo (120%) PGA 2/21/2013 1 Hz 2013 USGS NSHMP CA Workshop II 43

Hazard Curves: San Bernardino (88%) PGA 2/21/2013 1 Hz 2013 USGS NSHMP CA Workshop II 44

Hazard Curves: Oakland (82%) PGA 2/21/2013 1 Hz 2013 USGS NSHMP CA Workshop II 45

Hazard Curves: Cucamonga (50%) PGA 2/21/2013 1 Hz 2013 USGS NSHMP CA Workshop II 46

Hazard Ratios: PGA vs. 1 Hz 2/21/2013 USGS NSHMP CA Workshop II 47

Hazard Ratios: PGA vs. 1 Hz 2/21/2013 USGS NSHMP CA Workshop II 48

Hazard Ratios: Logic-Tree Weight Variation 2/21/2013 USGS NSHMP CA Workshop II 49

Continued UCERF 3 analysis… • Branch averaged solutions • Deaggregation • Stacked histograms of ground motion distribution at sites for each logic tree node (branch correlations) • Repeat convergence and equation weight tests • Higher resolution maps around San Francisco and Los Angeles • Hazard analyses online: – http: //opensha. usc. edu/ftp/pmpowers/UCERF 3. 2/ 2/21/2013 USGS NSHMP CA Workshop II 50